Art of ice making



March 12, 1935. D, K WARNER 1,994,183

v ART OF ICE MAKING Filed Jan. 16, 1930 2 Sheets-Sheet 1 IN VEN TOR.

March 12, 1935. K, WARNER 1,994,183

ART OF ICE MAKING F led Jan. 1 1930 2 Sheets-Sheet 2 n 8+ 0 a K E I @41 5 4 T 1 74 6Q 4,e V I 1 A A, ,4 V V 3 INVENTOR.

Patented Mar. 12, 1935 UNITED STATES A'lENT OFFICE r 13 Claims.

' This invention relates to improvements in, the process of the manufacture of-ice by what is known as direct expansion, which means evaporation of the liquid refrigerant directly adjacent to thewater being frozen as compared with the usual practise of first cooling brine, .--and with it freezing water. One manner of so freezing ice was shown in application of Nov. 9, 1927 becoming Patent N0.'1,884,428 issued Oct. 25, 1932. This method has been combined with apparatus shown in application filedApril 20, 1928 Serial No. 271,632 which was later combined-with application; Serial No. 277,931 and issued in Patent No. 1,928,580 together with several new improvements presently to be disclosed,

1 to make a cheaper and more efficient plant. The

purpose of the improvements are topermit of thawing the ice loose from the can walls with a minimum number of valves, a minimum of labor, and a minimum loss of refrigeration. The last object is obtained by not using condenser'gas for thawing, -but,.using instead, gasgenerated by initial cooling of the can water-and the precooling of the liquid refrigerant. The minimum number of valves is attained by using three-way cocks of special design and a new, non-gas return, float ball check, which permits the liquid to be rapidly forced out of thecan walls and when out, sinks and checks escape of gashbut stillpermits a very small stream of liq' uid to run out as it is. condensed by the thawing of the ice. Another improvement is in the method of preventing ice formations catching at the openings in the bottom of thecan where the water is either circulated in or .out. This is accomplished by doing no freezing at the bot? tom of the can but instead condensing some gas there a few hours before pulling time and again when thawing, this being accomplished without any extra labor, operations.

The invention may be better understood by referring to the drawings in whichsheet one Fig. 1 shows a cross section thru the ice tank, the liquid circulating and gas separating pipes, the intermediate pressure liquid receiver and water and ammonia forecooler, the condenser and compressor and "two necessary float valves such as shown in my Patent No. 1,761,000 issued June 3, 1930. Fig. 2 shows a plan of the top of the tank; Fig. 3 is a section of the can wall. Fig. 4 sheet two shows a section of another tank, the compressor and condenser not appearing. Fig. 5- is a part plan and part section of another single can. Similar numbers refer to similar parts in the various figures, 0 represents a float check valve the purpose of which is to of limiting the distance upwards which ball :1:

,may travel. Valve port 63 drains liquid while ball a: is up. While the liquid is being forced downward thru the valve by the thawing vapors the ball floats and permitsrapid escape of the liquid thru the main orifice 63 and also thru a small hole 61. Assoon as the liquid is out the ball :2 drops and closestne main outlet while the small hole 61 remains open to carry off additional refrigerant condensate from the thawing process which would otherwise be trapped above the ball as the ball buoyancy would not suffice to lift it from the seat once it had dropped anda pressure difference had been set up across the port 63. Removal of the thawing vapor pressure and reversal of liquid flow to freeze a new ice cake again lifts the ball a. 4

In Fig. 1 gas is compressed in compressor 6 and flows to condenser 1 and the outside of watercooled tubes B. Liquid drains to highpressure float valve 2, the float rising drains all the liquid without breaking the seal into receiver 3 and the pressure i113 forces the liquid on up to constant level float valve 4, which is similar to the first valve only upside down. At a predeter-v mined level its float rises and shuts off the liquid. Drum 5 is maintained abouthalf full of liquid and this liquid circulates by gravity orpower thru down, pipe 7 .and lower header 8. Liquid rises thru valve 9 and pipe 10 to the lower section of the end can wall. It passes thru the lower section of can walls 12 and. up passages 41 between the electric roll welded seams 13 to upper section 14. and thence thru valve -15 back to evaporating drum 5 where .part of the liquid evaporates due to the heatlgained in circulation thru the ice freezing walls and the balance of the liquid recirculates as before. L

The gas passes 01f thru pipe S to the suction valves of the compressor. The liquid passing between the float valves cools'itself by liberating gas into the receiver 3. This receiver also absorbs the variations in flow of the two valves and in addition houses the pipes A for the make. up waterwhich is cooled by passing thru them. The intermediate pressure gas passes oifthru pipe 16 and pressure regulating valve 50 to a multiple effect port 62 on the compressor 6. Here it compresses the low pressure gas which the cylinder has previously sucked in thru S and the whole is further compressed and sent to the condenser 1. When thawing, part of the intermediate pressure gas passes thru pressure regulating valve 51 to hand valve 17. Thence it passes thru the partitions in the bottom of the can and around the water openings 36 and 37 back thru pipe 13 to the top and end of the can Wall thru passage I l-down thru -41 and out thru 12,10 and 9 to the liquid pipe 8. The liquid valve 9 mustbe nearly closed sothat the -gas pressure may build up enough to thaw the ice but still permit the condensed liquid to escape.

In Fig. 4 an automatic valve 29 fdo'es'fthis work. A hollow ball lighter than the refrigerant floats out the ball settles on its seat and 'could not again be lifted by the liquid until the pressure has been removed from above it. ;25

For this reason a small hole is drill'ed'thru its :seatsuiiicient to pass off the required liquid without letting much gas escape. During-the thawing valves 15 or K have 'been closed to the drum '5.

In Fig. 4 valve 17 is operated by a pullrod P and handle N. Pipe 18 instead of passing at once lIItOZt hB-C EIJII wall goes to the three-way cock K; In operating, valve 17 is opened 3 or '4 hours prior to "thawing-time. Gas passes into walls D, E

:and 'H until condensation has entirely filled the space-with liquid. Then no more thawing can take placeuntil valve K is opened to 1'8 and closed 7 to gas liberating header 5.. Thiscondensationhas been sufficient to prevent the ice building out around thel ip-of 39 and still has-not causeda core the bottom as at the top it all freezes at about the same time and the '7 hour wait while the last- "inch is'freezing at the top of the ordinary block is eliminated and with 'itgo two other important losses. The first is that the long wait permits the lower part' of the block to absorb much refrigeration in unnecessarily 'lower'ing'its whole temperature to that of the cooling medium and the second is that having become'socold-it thaws very slowly and much ice is melted from the top of "the cake while waiting for the bottom to loosen.

No taper is needed on these cans for the water coming up thru the big passages 36 and 3,7 lifts and follows after the ice as it is pulled and the long can walls could easily bend out if necessary to the openwater on the side where the ice has just been pulled. f

The water is circulated in the cans by means of the revolving tube 32 which runs the length of the tank and circulates the water in all the cans with the aid of a paddle 33 on eachside ofit. The paddles come in close contact with the shell 44 and the water is forced around with the paddles causing a continuous stream of water to flow to the right at the bottom of shell i l. This draws otherwater from the tank SObeloW the cans pipe 24'.

as when there is 300lbs. in it, though it obviously j .needs only one tenthas'much'so that in order to have the required agitation during the first hour nearly 10 times too much power is used the other '39 hours. 'Air'agitation beingineiiicient at best a decided-gain is made by changing to water agitation and a clear ice from the poorest Water is possible just as the ice is formed clear in fast running streams. v The construction-shown saves freezing time by eliminating ice taper 'anddelayin freezing where a'thic'k top end o'f the cakeis required because of' uneven thawing means and lack" of positive removalimeans. Less can met'al'is required forfit also. 1 V The space-between cans -being=eliminated a further great savingin the cost of the building is involved- Othersavings are the cost of the brine tank; air compressor, air laterals and system, can

dumppcan fillers, dip "tank, core pump,-core's'u'ckers, etc-.',--but more particularly the labor saved by eliminating the above mentioned articles and the requirement of slowly thawing an air tube f-romevery ice cake. I I V As in-former'disdosures the water from the bottom of the tank in front of baffle 20 is being continually d'rawnfoff thru:21-and pump 22, threeway clean-out cock 26, sand filter 23,1and back F to tank 3 0: t'hru secondthree-waybock 2jjan d" Only one side I time. The other side which-had been thawed for the previous "cake is left with both the freezing valve K and thawing valve N'closed'until theadjacent cake is pulled, when freezingis com mencedagain on'one side of the cake just pulled.

witha bottom strip under the .wall'2 inches wide make a can wall assemblysunit. It is made of two,- ten by four ft. 12 gage cold rolled steel sheets sages 12 and 14 being left unwelded an unj I stamped so as to permit therefrigerant to travel spot or roll weldedtogether at marks 13, the pa s across the tank. The top edgesare arc welded-to 'gether, adiamond shaped plate being welded over the. top of the marking grooves. These plates wall of'jone c'ani is thawed at a a Each can wall and every bottom is a separateunit and any one maybe pumped; out and replaced 5. without disturbing the others or taking the gas out of them; Qne side and two end walls together support the can covers which in turn support the lifting hooks T. "Ihe lifting hooks consist M of a single strip of flat German silver or other high resistance metal with an eye at either end to engage with a double pointed crane hook. The

high resistance strip extends downintothe water I on one-side of the can center line and back up on the other side with about a A inch space between the two so that it would'be possibleto thaw, a

by the needle hot water method, in case elec-' tricity was not available for the purpose at any time. 'The hooks are left in the ice duringstora age and until the ice is-set .onthe scoring'mw chiner 'lhepulling crane takes the. ice directly to its place in the'store room and. also back to the scoring table. It lowers the ice while it is being scored vertically in the grooves on one side only. Then a lowvoltage current is turned on to the double pointed crane hooks permitting the current to pass into the ice hook thru :one eye and back through the other. The high resistance soon loosens the hooks by the heat formed andthe hooks are pulled up by the :crane. The ice is then tipped downpnto the scoring table with the vertically scored side at the bottom.

Conveyor chains now carry the ice sheet lengtha wise between upper and lower banks of saws located at the center of the table at the outer wall of the building. As the ice is sawed it, passes thru the wall opening, onto the outer half of the table and directly onto the truck. The sheets are frozen in lengths so as to just fit the average truck or about 1500 lbs. per sheet. Usually two sheets make a load and before the second sheet comes out the truck driver raises the outer edge iof the table which is pivoted at its center and the second cake slides easily on top of the first; The ice being scored both ways on the bottom the driver 'has only to'touoh the top groove or score mark with his pick to break the ice where he desires.

The shrinkage and breakage during delivery reduced by keeping the ice all in one piece. The driver need not know how to cut ice or handle the big cakes on the platform. His only duty is to politely deliver pieces of ice, allexactly uniform in dimensions. His troubles in getting the thick ends of a cake into an ice box a little too small are over. His time of cutting and loading the ice saved, so that in a given time he can deliver twenty percent more ice, increasing his earnings accordingly. The manufacturer is not faced with the diflicult proposition each summer offinding skilled and honest ice cutters, and not being required to move heavy ice blocks a .light man can do the work easier than a heavy man since about to be welded to the next, a single strip of metal extends almost an inch beyond the double section. The edge ofthis strip is dipped in acid to remove the galvanizing. It is'then bead welded on the outside and soldered smooth on the inside and Zinc sprayed, or painted over the weld on the outsideof the can. The bottom section consists of a double welded sheet starting at D passing around opening 36 at E, being cut away at the end of E to permit the blades of agitator 32 to revolve. A small passage for the gas is still left and the sheet is now turned up horizontally at .5 its lower edge now being brought up to the center line of the can. It continues in thispositio-n for various distances depending on the length of cake desired for the delivery trucks used. Then it bends down again at 39 for opening 37 where the circulating waterleaves thecan. It passes around this opening, is bent back up to reach the center of the can thus forming a split but continuous bottom. It then passes around the inlet water opening similar to the other side E to the outlet opening at E. Short nipples are welded into D and H, and these pass out thru stuffing b Xes in the tank wall and are, then flanged to their respective pipes. strips are welded at V to the bottom strip of the ammonia suction pressure of 32 lbs.

These bottom can wall. If the bottom must be replaced the weld V is out, the flanges unscrewed from the nipples; and 'the bottom drawn up thru the can, a new bottom sheet inserted and soldered at V. :Columns 27 support the can walls and hold the bottom sheets in place, holding both down While theice is being pulled. If a leak developed in a bottom or a can wall, valves 1'? and K would be closed to 3 and 5 and valve 38 would be closed to 8 and the connection opened to pump out-the ammonia. It would then be left till an off peak season, ice being pulled from this particular cell only half as often since now only half a block would freeze from one side in the regular period and when the adjoining cake was being thawed this halfcould either be pulled for 5 inch ice or pushed over to the other side to wait till another half froze. V

Agitator 32 is made of a tube the full length of the tank driven by a shaft extending ,thru

the tank at one end and fixed in a bearing at the other end. The ends of the tube are sealed and its weight including the paddles 33 is such that thewater just supports it so permitting a long agitator without anyb-ending strains or loads on the bearings.

A 32 ft. tank would be divided'into 36 cells freezing inch ice. Assuming the trucks tobe 8 ft. long-and the ice 46 .inches high the tank would make tons of ice per day with an A cake of ice must be pulled every 5.0 minutes. It is desirable that the thawing temperature 'thm be adjusted so that the next cake may be started thawing at this time and just be ready to pull when the man comes back fifty minutes later. This may be closely; regulated by adjusting pressure regulating valve 50. .In winter theflow of gas would need to be checked at 50 .onaccount ofthe smaller amount of work to be done in forecooling ammonia andfeed water and in summer in small plants where the pulls are about anhourapartand a 34 deg. temperature is sufiicient forthawing, it might be desirable to reduce the pressure formed either by reducing valve or a connection to another multiple effect port further along in the ammonia cylinder, both ports being kept open in summer and only a smallone at the very end ofthe stroke open in WlllteI2 Y I The pressure regulating valves maybe either automatic or hand operated-as hand operation would require very little attention, and there would, be no great loss even if the ice thawed loose considerably beforethe'pulling' time as 1 the low temperature could melt little ice and what anythawing. The method; of thawing has another advantagein addition to its efficiency. The

I pressure in the canwalls'is limited to between 50 to 60 lbs. whereas with condenser gas the pressure would be very variable and might go to 250'lbs. This therefore permits of greater spacing and fewer welded seams in the can walls.

To operate the tank inFig. 4 rod N is pulled up opening valve 17 three hoursbefore pulling time. It is left up K has been opened and the ice thawed loose. The ice is pulled and K or 1'! closed but K is kept closed and not reopened until the cake of ice' adjoining on the other side has been pulled. The cover is lifted with the ice and the only other operation consists of putting it back onthe can and inserting two ice hooks in its slots. Each time a cake is pulled the man closes a pair of valves K and N and opens another pain four operations requiring seconds time.

What I claim as my invention and secure by Letters Patent, is:

1. A process of thawing ice consisting. of producing a refrigerant gas at'a pressure between that in the condenser and themain evaporator desire to by evaporating liquid leaving the condenser, by

its own heat and then condensing said gas on the evaporator surface.

v2..A process of thawing ice for easy removal from evaporator surface by evaporating liquid refrigerant with the heat of water to be used in the making of the ice and conveying the heat in the form of refrigerant vapor-at a pressure intermediate between that in the condenser and evaporator and condensing said vapor on the evaporator surface in such manner that the ice water is cooled preliminary to being frozen by supplying the heat for evaporating liquid to thaw the ice.

'3. The process of manufacturing ice in containers in'the walls of which the refrigerant is evaporated and later condensed for thawing the rice loose, which consists of producing vapor for thawing the ice by a combination of liquid evaposration caused by reducing the pressure of the :liquid refrigerant leaving the condenser, thereby 1 cooling. this liquid, and liquid evaporation caused by absorbingiheat from the water to be used in zicemaking.

ljThe process ofmanufacturing ice in conltainersin the walls of which the refrigerant is, pevaporated'forfreezing ice and condensed for 'z thawing ice looseythe vapor for thawing the ice -;loose: being produced by evaporation of refrigerant: in absorbing:heat from the liquid refrigerant :and from the "water to'be used in ice making, and saidithavrlngivapor having its pressure held ap- -proximately constant at a desired'pressure intermediatebetween that in the condenser and evaporator by'a pressure reducing valve admitting surplus vapor into the compressor after the comp'ressor cylinder has been filled with low pressure gas produced by forming the ice.

'5. :The process .of manufacturing ice in containersinthe walls. and bottom of which liquid refrigerant is first evaporated and circulated to -receiveheat for evaporation in an evaporating compartment whichconsists of stopping the flow of vapor and liquid to said evaporating compartmentupon'complete'freezing of the ice and introducing :refrigerantvapor formed by precooling' the liquidrefrigerant to thaw and loosen the ice. 7

6. -The,process,of manufacturing ice by admitting and evaporating liquid refrigerant in the' walls and bottom of an :evaporator container and laterthawing the ice-loose by introducing vapor formed byprecooling the water, and refrigerant,

= thebottom prior to evaporation in the walls and introducinga thawing vaporinto the bottomprior :to introducing itrto the side walls and removing the condensed liquid to the evaporator circulating system without permitting the condensing vapor. V V

to escape to the evaporator system.

9. Ice making. apparatus consisting of a plurality ofv containers with hollow walls for refrigerant circulationyhollow bottoms withlike provision and. openings at each end of thebottomsto permit an easy circulation of water up into' the container at one end and out at theother end and thru a compartment under and common to all containers in which is located means for circulating,

the water; means'for circulating an evaporating refrigerant'thru the walls of .the compartments to freeze the ice and means for PIOdllOillgfiQthflvW- ingvapor at a pressure intermediatebetween-that in the condenserand evaporator by' reducing the pressure of the liquid leaving the condenser and means'for introducing said vapor into theflwalls;

and bottom; of the compartment forthawing ice.

10. Ice making apparatus consisting of a plurality of containers with hollow walls'for circulating evaporating refrigerant, disposed above" a common water circulating and sediment collecting tank, means for circulating the waterby a longitudinally finned pipe revolving within .a partial casing; together with means for. circulating the refrigerant while freezing the ice and meansifor evaporating and precoolingthe condense'darefrigerant in an intermediate pressure cooler and means for introducing the intermediate pressure vapor to the container walls and means to permit escape of liquid from the walls and preventiescape of vapor to the evaporating system.

ll. Ice making apparatus consisting of aplurality of containers with hollow walls for circulating evaporating refrigerant, disposed above 3.

single watercirculating tank and means for-cir culating water thru said tank and thru openings in the compartment bottom so disposed as tocause a the water to circulate from end to end'in the compartments together with means for producing vapor to introduce intothe can walls for thawing the ice and means to prevent variationin said pressure by a relief valve interposed betweenfan intermediate pressure receiverand a compressor capable ofreceiving the gas at this pressure,

12. Icemaking appara s with a'pmralityy-d 5 7' containers with hollow walls for circulating evap orating refrigerantdisposed above. a common water circulating tank and means for circulating water thru said tank and continuously separating and filtering the water in this tank andprovisiom in the bottom of the containers for circulating the water up into one end of the container thru it and down out at the other end together with meansforproducing refrigerantvapor at apressure corresponding to a temperature slightly above that of the melting point of iceby precoolingthe refrigerant liquid andthe icemakinglwaterl with means for maintaining that pressure by a pressure control valve interposed between anintermediate pressure receiver (containing a water cooling coil) anda connection to a compressor to receive vapor atfthe' end of a suction stroke-at=an I intermediate pressure together with means'for draining all the liquid from the condenser without passing any vapor and means for maintaining a constant level of liquid in the main evaporator and means for stopping the passage of vapor to the evaporator on each compartment'and means for introducing the thawing vapor thruthe. can

bottom and thence thru the can walls and of forcing the liquid out the bottom at the opposite end of the compartment and means for preventing the vapor following the liquid while still permitting the condensing liquid to escape to the evaporating system all substantially as shown.

13. The combination in a refrigerating apparatus including a condenser and a drain trap con- 7 nected therewith, an intermediate pressure receiver receiving drains from said trap as fast as 10 refrigerant vapors are condensed, constant level float valves connected with said receiver and drawing liquid from said receiver, low pressure evaporators connected with said valves last mentioned to maintain constant liquid levels in low pressure evaporators, means for removing vapors from 'evaporators and means for removing vapors from receiver at a pressure intermediate between evaporator pressure and condenser pressure.

DOUGLAS KENT WARNER. 

